ADJTIME man page on OpenBSD

Man page or keyword search:  
man Server   11362 pages
apropos Keyword Search (all sections)
Output format
OpenBSD logo
[printable version]

ADJTIME(2)		  OpenBSD Programmer's Manual		    ADJTIME(2)

     adjtime - correct the time to allow synchronization of the system clock

     #include <sys/time.h>

     adjtime(const struct timeval *delta, struct timeval *olddelta);

     adjtime() makes small adjustments to the system time, as returned by
     gettimeofday(2), advancing or retarding it by the time specified by the
     timeval delta.  If delta is negative, the clock is slowed down by
     incrementing it more slowly than normal until the correction is complete.
     If delta is positive, a larger increment than normal is used.  The skew
     used to perform the correction is generally a fraction of one percent.
     Thus, the time is always a monotonically increasing function.  A time
     correction from an earlier call to adjtime() may not be finished when
     adjtime() is called again.	 If delta is null, no adjustment is done.  If
     olddelta is non-null, the structure pointed to will contain, upon return,
     the number of microseconds still to be corrected from the earlier call.
     Setting the time with settimeofday(2) will cancel any in-progress time

     This call may be used by time servers that synchronize the clocks of
     computers in a local area network.	 Such time servers would slow down the
     clocks of some machines and speed up the clocks of others to bring them
     to the average network time.

     Only the superuser may adjust the time using the adjtime() function.

     A return value of 0 indicates that the call succeeded.  A return value of
     -1 indicates that an error occurred, and in this case an error code is
     stored in the global variable errno.

     adjtime() will fail if:

     [EFAULT]	   Either of the arguments point outside the process's
		   allocated address space.

     [EPERM]	   The delta() argument is non-null and the process's
		   effective user ID is not that of the superuser.

     date(1), adjfreq(2), gettimeofday(2), ntpd(8), timed(8), timedc(8)

     R. Gusella and S. Zatti, TSP: The Time Synchronization Protocol for UNIX

     The adjtime() function call appeared in 4.3BSD.

     Other operating systems restrict calling adjtime to the superuser and
     might not allow requesting the current correction without specifying a
     new value.

OpenBSD 4.9			 June 5, 2009			   OpenBSD 4.9

List of man pages available for OpenBSD

Copyright (c) for man pages and the logo by the respective OS vendor.

For those who want to learn more, the polarhome community provides shell access and support.

[legal] [privacy] [GNU] [policy] [cookies] [netiquette] [sponsors] [FAQ]
Polarhome, production since 1999.
Member of Polarhome portal.
Based on Fawad Halim's script.
Vote for polarhome
Free Shell Accounts :: the biggest list on the net